British Patent 2 095 611 B has already disclosed such a device with which the parisons are gripped on the outside in the head area by means of holding fingers between the supporting ring and the open mouth and the shielding is formed by a cylindrical protective jacket which surrounds most of the head area including the supporting ring. Although the parison head area, which is not to be deformed, is protected from direct heating by the radiant heater due to this protective jacket, it is not protected from indirect heating by the protective jacket, which is itself heated by the radiant heaters.
British Patent 2 095 611 B has already disclosed such a device with which the parisons are gripped on the outside in the head area by means of holding fingers between the supporting ring and the open mouth, and the shielding is formed by a cylindrical protective jacket which surrounds most of the head area including the supporting ring. Although the parison head area, which is not to be deformed, is protected from direct heating by the radiant heater due to this protective jacket, it is not protected from indirect heating by the protective jacket, which is itself heated by the radiant heaters.